The invention relates to a controller of an indicating board, in particular to an automatic controller of an indicating board for school bus parking. The automatic controller of the indicating board for school bus parking comprises a stepping motor used for controlling the indicating board for school bus parking to stretch out and withdraw, a stepping motor driver driving the stepping motor to work, a sound-and-light driving circuit used for driving an alarm, a caution lamp and an indicating lamp to work, a limiting control circuit used for detecting whether opening or closing of the indicating board for bus parking is in place or not, an operating signal detecting circuit used for selecting various working states, and a single-chip microcomputer used for controlling the stepping motor driver and the sound-and-light driving circuit to work, wherein the stepping motor driver, the sound-and-light driving circuit, the limiting control circuit and the operating signal detecting circuit are respectively connected with the single-chip microcomputer, the stepping motor is connected with the stepping motor driver, the stepping motor driver is further connected to a vehicle-mounted power source, and the sound-and-light driving circuit is further respectively connected with the vehicle-mounted power source and a grounding terminal. The automatic controller of the indicating board for school bus parking has the advantages of being accurate in positioning, capable of being controlled by a driver conveniently and rapidly and avoiding error operation, and the like.